Over a month ago I mentioned I was treated for SIBO. If it helped the digestive issues, it was subtle. I am however pretty sure it gave me Seasonal Affective Disorder.
Let me give you some context. I grew up in Rochester, NY (165 sunny days/year). I went to college in Ithaca, NY (152 sunny days/year, but less snow than Rochester). I’ve lived for Seattle (152 sunny days/year) for almost 8 years. Winter weather might keep me indoors more, and I do need vitamin supplements year round, but that’s because wet socks are unpleasant and I’m bad at metabolism. I didn’t have any SAD symptoms leading up to starting treatment for SIBO, which happened to be the day after winter solstice.
The treatment for SIBO for me was two antibiotics, erythromycin and xifaxan. Two or three days after I started, I felt fine during the day, but as soon as the sun went down it felt like the world was ending. It felt Late as soon as it was dark, which was 4:30 PM at the time. As time went on, I got more and more emotionally distraught and depressed. Everything felt awful.
1.5 weeks in, I noticed this, upped my vitamin D and started using a sun lamp, and that helped. 2 weeks in the treatment naturally ended, and I felt better still. But not all the way better.
Finally, almost six weeks after I’d stopped antibiotics, I remembered a friend telling me about inositol, which is a carbohydrate used for intercellular communication. The conventional wisdom is that your body can naturally manufacture enough inositol from glucose that nutritional sources are irrelevant: however, there’s some evidence that it’s either made or affected by your intestinal flora.* I’d tried it when he suggested it and found it had no effect, but kept the bottle just in case. I gave it another shot, and felt better the next day. 2 weeks in, I feel like the SAD is completely gone.
Right on the web page, there’s a warning that Xifaxan can cause an overgrowth of Clostridium difficile. In the study my friend described but did not give me a proper citation for, he said the researchers had isolated six different bacteria that competed with C. difficile, one of which produced inositol. I cannot find this study, or even a news article, anywhere.
It’s hardly proven, but I have a strong hypothesis that the antibiotics screwed up my intestinal flora (which is, in fact, what they were supposed to do, we were just hoping to localize the effects to the small intestine), leading to an inositol deficiency, leading to SAD. In many ways my digestive system feels like it’s been bumped back to earlier stages of treatment (the HCl supplements and removing some food groups), which makes me think that some of the things I experienced were second order effects of changing intestinal flora, rather than my diet directly.